Original Folders

I have rooted my phone and began to venture into the folders of my eris while installing ROM's. Now the GPS does not work and am trying to unroot droid and wanted to know if anyone has a list of the original folders i should have on the eris and files along with them. Does anyone know of a link that might supply this.
Most websites explain procedure on Windows and im running a MacBook.
Any help is greatly appreciated
Thanks